Systems and methods for providing updated mobile station location estimates to emergency services providers

ABSTRACT

A wireless communication system, including apparatuses and methods, for handling emergency calls from wireless communication devices to emergency services providers and for automatically providing updated location estimates for the wireless communication devices to during such emergency calls absent any request therefor. The updated location estimates are generally provided in response to a detected occurrence of a triggering event within the wireless communication system. In the exemplary embodiments, such triggering events include the passage of a pre-determined threshold period of time and the handover of an emergency call between cells or sectors of the wireless communication system in response to movement of the wireless communication device from which the emergency call is being made. Further, according to at least one exemplary embodiment, the wireless communication system may selectively limit the provision of updated location estimates based on whether movement of a wireless communication device is substantial or insubstantial.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to the field of wirelesscommunication systems and more particularly to wireless communicationsystems and methods for automatically providing updated locationestimates for wireless communication devices to emergency servicesproviders during emergency calls.

2. Description of the Related Art

A person desiring emergency services in most areas of North America mayplace an emergency call to an appropriate emergency services provider(e.g., a governmental public safety organization responsible for theprovision of such services) by dialing the digits “911” on a wired orwireless communication device. The emergency call is then routed andconnected to a dispatcher located at a public safety answering point ofthe emergency services provider. Soon after communicating certain basicinformation to the dispatcher, the person (i.e., the caller) generallyreceives emergency services from police, fire, or paramedic personnel asappropriate.

When such an emergency call is made by a caller using a wirelesscommunication device, the caller's wireless service provider must alsoprovide certain data to the emergency services provider. The requireddata is specified by governmental regulations pertaining to the handlingof emergency calls originating from a wireless telephone or otherwireless communication device. The governmental regulations are commonlyreferred to as “e911” regulations and currently include two sets, orphases, of regulations. For the wireless service provider's network tobe compliant with the first phase of the e911 regulations pertaining tosuch calls (e.g., the Phase I e911 regulations), the wireless serviceprovider must provide the telephone number of the caller's wirelesscommunication device and the street address of the cell tower providingservice to the caller's wireless communication device. Alternatively,for the wireless service provider's network to be compliant with thesecond phase of the e911 regulations pertaining to such calls (e.g., thePhase II e911 regulations), the wireless service provider must providethe latitude and longitude corresponding to a location estimate for thecaller's wireless communication device in addition to the information ordata provided in accordance with the Phase I e911 regulations.

According to the Phase II e911 regulations, the wireless serviceprovider's network generally provides an initial location estimate(including, but not limited to, the latitude and longitude of thelocation estimate for the caller's wireless communication device) to thepublic safety answering point of the emergency services provider uponrequest therefrom once a voice communication path is established for theemergency call. Subsequently, the dispatcher at the public safetyanswering point may optionally request updated location estimates forthe caller's wireless communication device during the emergency call,but the wireless service provider's network provides such updatedlocation estimates only in response to such “pull” requests.

The ability to issue such “pull” requests to the caller's wirelessservice provider and to obtain corresponding updated location estimatesis extremely important to the dispatcher in those situations where thecaller is not substantially stationary. However, in many cases, thedispatcher may not know that the caller is moving until a “pull” requestfor an updated location estimate is made and the wireless serviceprovider's network provides an updated location estimate indicating thatthe caller's wireless communication device has moved from the latitudeand longitude associated with the initial location estimate. In thosecases where the dispatcher knows that the caller is moving, thedispatcher may not know how fast the caller is moving and, as aconsequence, does not know how frequently to request updated locationestimates. If the dispatcher requests updated location estimates toofrequently, the wireless network resources required to provide suchestimates may be unnecessarily tied up. Alternatively, if the dispatcherrequests updated location estimates too infrequently, the dispatcher maynot know the location of the caller's wireless communication device withany reasonable degree of certainty and, hence, cannot accurately directpublic safety personnel to the caller's current location. To furtheraggravate these difficulties, there is always a chance that an updatedlocation estimate may not be as accurate as the initial locationestimate.

Notably, in the majority of emergency call situations, the caller makingthe emergency call is stationary or substantially stationary. As aconsequence, the provision of updated location estimates in suchsituations in response to dispatcher “pull” requests is unnecessary andprevents valuable wireless communication network resources from beingutilized for other purposes.

Therefore, there exists within the industry a need for wirelesscommunication system and methods for providing an emergency servicesprovider with updated location estimates for a caller's wirelesscommunication device during an emergency call that addresses these andother problems or difficulties that exist now or in the future.

SUMMARY OF THE INVENTION

Broadly described, the present invention comprises a wirelesscommunication system, including apparatuses and methods, for handlingemergency calls from mobile stations to emergency services providers andfor automatically providing updated location estimates for the mobilestations to the emergency services providers during such emergency callsand absent any request therefor. More particularly, the presentinvention comprises a wireless communication system, includingapparatuses and methods, for automatically providing such updatedlocation estimates in response to the detected occurrence of atriggering event within the wireless communication system. For exampleand without limitation, one such triggering event includes the passageof a pre-determined threshold period of time. Another such triggeringevent includes, for example, the handover of an emergency call betweencells or sectors of the wireless communication system in response tomovement of the mobile station from which the emergency call is beingmade. Thus, the automatic provision of updated location estimates by thewireless communication system may be periodic or non-periodic. It shouldbe understood, however, that the scope of the present invention is notlimited only to the triggering events described herein.

In the exemplary embodiments, the wireless communication system of thepresent invention establishes a voice communication path between amobile station, or wireless communication device, and an emergencyservices provider (e.g., a public safety organization of a governmentalunit) upon receiving a request for an emergency call produced by a userof the wireless communication device placing a “911” call. Thereafter,the wireless communication system handles the emergency call inaccordance with at least the Phase I and Phase II e911 governmentalregulations pertaining to emergency calls originating from a wirelesscommunication device, including the provision of an initial locationestimate and updated location estimates for the wireless communicationdevice in response to requests for such estimates (e.g., “pull”requests) received from the emergency services provider. Additionallyand inventively, the wireless communication system of the presentinvention automatically determines and communicates updated locationestimates for the wireless communication device to the emergencyservices provider during the emergency call and does so absent anyrequest therefor. Because the communication of such updated locationestimates to the emergency services provider is performed automaticallyby the wireless communication system and is initiated solely within thewireless communication system not in response to anyexternally-generated requests therefor, such updated location estimatesare referred to as being “pushed” to the emergency services provider bythe wireless communication system of the present invention. In order totrigger the “pushing” of such updated location estimates, the wirelesscommunication system of the present invention is configured to detectthe occurrence of a triggering event occurring therewithin with respectto the emergency call and, in response, to determine and “push” suchupdated location estimates to the emergency services provider. Further,in accordance with at least one exemplary embodiment, the wirelesscommunication system may selectively limit or control the automaticprovision of such updated location estimates based on an evaluation ofrelated triggering conditions, including, for example, an evaluation ofwhether a handover of an emergency call between cells or sectorsconstitutes substantial or insubstantial movement of the callingwireless communication device.

Advantageously, by automatically determining and “pushing” updatedlocation estimates to emergency services providers during emergencycalls from wireless communication devices, the wireless communicationsystem of the present invention allows dispatchers of emergency servicesproviders to know whether the wireless communication devices arestationary or moving and thereby minimizes the need for dispatchers torequest updated location estimates in order to make such a determinationon their own. Also, such automatic determination and “pushing” ofupdated location estimates enables dispatchers to know the most recentlocations of the wireless communication devices with improved certaintyand, hence, allows dispatchers to more accurately direct emergencyservices responders (e.g., public safety personnel) to the callers'respective locations. As a consequence of providing dispatchers withbetter information related to the stationary or non-stationary nature ofcallers' wireless communication devices and their current locations, thewireless communication system of the present invention may substantiallyreduce the number of unnecessary “pull” requests for updated locationestimates that are generated by the dispatchers of emergency servicesproviders and, therefore, improve the utilization of valuable wirelesscommunication network resources.

Other advantages and benefits of the present invention will becomeapparent upon reading and understanding the present specification whentaken in conjunction with the appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram representation of a wireless communicationsystem for handling emergency calls from mobile stations to publicsafety answering points of emergency services providers in accordancewith the exemplary embodiments of the present invention.

FIG. 2 is a flowchart representation of a method for handling anemergency call from a mobile station and for automatically providingupdated location estimates for the mobile station to a public safetyanswering point of an emergency services provider during the emergencycall in accordance with a first exemplary embodiment of the presentinvention.

FIG. 3 is a flowchart representation of a method for establishing avoice communication path between a mobile station requesting anemergency call and a public safety answering point of an emergencyservices provider in accordance with the exemplary embodiments of thepresent invention.

FIG. 4 is a flowchart representation of a method for determining andcommunicating an initial location estimate for a mobile station to apublic safety answering point of an emergency services provider inaccordance with the exemplary embodiments of the present invention.

FIG. 5 is a flowchart representation of a method for determining andcommunicating an updated location estimate for a mobile station to apublic safety answering point of an emergency services provider inaccordance with the first exemplary embodiment of the present invention.

FIG. 6 is a call flow diagram of messaging associated with the initialset up of an emergency call from a mobile station to a public safetyanswering point of an emergency services provider by the wirelesscommunication system in accordance with the exemplary embodiments of thepresent invention.

FIG. 7 is a call flow diagram of messaging associated with the automaticdetermination and communication of updated location estimates for themobile station during an emergency call in accordance with the exemplaryembodiments of the present invention.

FIGS. 8A-8B are flowchart representations of a method for handling anemergency call from a mobile station and for automatically providingupdated location estimates for the mobile station to a public safetyanswering point of an emergency services provider during the emergencycall in accordance with a second exemplary embodiment of the presentinvention.

FIG. 9 is a call flow diagram of messaging associated with the detectionof a handover of an emergency call from a mobile station to another cellor sector in accordance with the second exemplary embodiment of thepresent invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings in which like numerals represent likeelements or steps throughout the several views, FIG. 1 displays a blockdiagram representation of a wireless communication system 100 forhandling emergency calls from mobile stations 102 to public safetyanswering points 104 (sometimes referred to herein as “PSAPs 104”) ofemergency services providers in accordance with the exemplaryembodiments of the present invention. Generally, the mobile stations 102(sometimes referred to herein as “MSs 102” or as “wireless communicationdevices”) include wireless telephones, wireless voice and datacommunication-enabled personal digital assistants, wireless voice anddata communication-enabled computing devices, and other devices havingsimilar wireless voice and data communication capabilities that are, orbecome, available now or in the future. Each public safety answeringpoint 104 is, typically, associated with an emergency services provider(also sometimes referred to herein as a “public safety organization”) ofa governmental unit (e.g., city, township, county, parish, or othersimilar unit) and comprises appropriate communication and/or computerequipment that enables a dispatcher of the public safety organization toanswer and talk with a caller during an emergency call. If suchequipment is compliant with the Phase II e911 regulations, it is adaptedto display the phone number of the caller's communication device (suchas, for example, a mobile station 102) and an initial location estimateof the caller's communication device based on data requested andreceived from a communication network (such as, for example, wirelessnetwork 100) handling the emergency call. Additionally, such equipmentis operable to generate and communicate requests for data representingupdated estimates of the then current location (sometimes referred toherein as an “updated location estimate”) of the caller's communicationdevice from the communication network as directed by a dispatcher, toreceive and acknowledge receipt of data corresponding to updatedlocation estimates, and to display the then current location of thecaller's communication device based on the received updated locationestimates.

The wireless communication system 100 (sometimes referred to herein as“wireless communication network 100” or “wireless network 100”)comprises a gateway mobile location center 106, mobile switching center108, base station controller 110, serving mobile location center 112,and a plurality of transceivers 114. Generally, these components of thewireless network 100 are configured to operate and handle wirelesscommunications and signaling according to the global system for mobilecommunications (“GSM”) protocol. However, it should be understood thatthe scope of the present invention includes all wireless communicationsystems and/or networks that may operate or be configured to operateaccording to other protocols and as described herein. It should also beunderstood that even though much of the description herein is directedtoward the handling of a single wireless emergency call by the wirelessnetwork 100 for purposes of convenience and clarity and that, as aconsequence, only single wireless network components of a particulartype are referred to as providing the functionality described herein,the wireless network 100 may handle a plurality of emergency calls froma respective plurality of mobile stations 102, automatically provideupdated location estimates for such respective plurality of mobilestations 102 to a respective plurality of public safety answering points104, and employ multiple wireless network components of a particulartype as appropriate to provide such functionality.

The gateway mobile location center 106 (sometimes referred to herein as“GMLC 106”) comprises a processing unit, a data storage device storing adatabase and software program instructions executable by the processingunit, memory, and appropriate data communication interfaces. The gatewaymobile location center 106 is adapted to communicatively connect to awireless automatic location identification system 105, via datacommunication interfaces of the gateway mobile location center 106 andwireless automatic location identification system 105 and bi-directionalcommunication link 116, during the handling of an emergency call from amobile station 102. The wireless automatic location identificationsystem 105 (sometimes referred to herein as “wireless ALI 105” or “W-ALI105”) is configured to communicatively connect, during an emergencycall, to the communication equipment of an appropriate public safetyanswering point 104 through its own data communication interfaces andbi-directional communication link 117. The W-ALI 105 is furtherconfigured to communicate initial location estimates for mobile stations102 to the appropriate public safety answering points 104 in response torequests therefor and to communicate, or “push”, updated locationestimates for mobile stations 102 to the appropriate public safetyanswering points 104 absent any requests therefor from such publicsafety answering points 104. Hence, by virtue of the W-ALI 105,bi-directional communication links 116, 117, and respective datacommunication interfaces, the gateway mobile location center 106 isadapted to connect during the handling of an emergency call to anappropriate public safety answering point 104 for the bi-directionalcommunication of information, data, and/or signals therewith. It shouldbe noted that, although described herein with respect to exemplaryembodiments of the present invention as a separate component, the W-ALI105 might be integral with the gateway mobile location center 106.

The gateway mobile location center 106 is further adapted tocommunicatively connect to a mobile switching center 108, via the GMLC'sdata communication interfaces and bi-directional data communication link118, during the handling of an emergency call from a mobile station 102.Generally, bi-directional communication link 116 is based on theInternet Protocol, bi-directional communication link 117 is based on aproprietary interface of the vendor of the W-ALI 105, and bi-directionalcommunication link 118 includes an SS7 switch. It should be understood,however, that other forms of bi-directional communication links 116,117, 118 might be employed within the scope of the invention.

During operation, the processing unit of the gateway mobile locationcenter 106 executes the GMLC's software program instructions such thatthe gateway mobile location center 106 is operable to perform accordingto the methods described herein and to bi-directionally communicatemessages, signals, and data with the public safety answering points 104(i.e., via an appropriate W-ALI 105 and bi-directional communicationlinks 116, 117) and mobile switching center 108 through bi-directionaldata communication link 118. More particularly, the gateway mobilelocation center 106 is operable to: receive an initial message from themobile switching center 108 for an emergency call that includes theemergency services routing digits and phone number for the mobilestation 102 from which the emergency call originated; assign anemergency services routing key to the emergency call and return same tothe mobile switching center 108; instruct the mobile switching center108 to set up a voice communication path 140 between an appropriatepublic safety answering point 104 and the mobile station 102; receivemessages from the public safety answering point 104 (i.e., via anappropriate W-ALI 105 and bi-directional communication links 116, 117)requesting data representative of the phone number, initial locationestimate, and updated location estimates of the mobile station 102;communicate messages to the public safety answering point 104 (i.e., viaan appropriate W-ALI 105 and bi-directional communication links 116,117) in response thereto that include such data; and exchange messageswith the mobile switching center 108 to receive and acknowledge thereceipt of data representative of the initial location estimate of themobile-station 102.

The gateway mobile location center 106 is further operable during anemergency call to: initialize and re-initialize trigger-related timersand/or conditions; communicate messages to the mobile switching center108 requesting data representative of updated location estimates of themobile station 102 upon occurrences of a triggering event andsatisfaction of trigger-related conditions, if any; receive messagesfrom the mobile switching center 108 including such data in response tosuch requesting messages; communicate, or push, messages including datarepresentative of updated location estimates of the mobile station 102to the public safety answering point 104 (i.e., via an appropriate W-ALI105 and bi-directional communication links 116, 117) upon occurrences ofa triggering event and satisfaction of trigger-related conditions, ifany, and absent requests for such data from the public safety answeringpoint 104; and, receive messages from the public safety answering point104 (i.e., via an appropriate W-ALI 105 and bi-directional communicationlinks 116, 117) acknowledging the receipt of data representative ofupdated location estimates of the mobile station 102 so pushed to thepublic safety answering point 104. The gateway mobile location center106 is still further operable to access enablement data in the GMLC'sdatabase that designates whether the provision, communication, orpushing, of data representative of updated location estimates for mobilestation 102 is enabled for the mobile switching center 108, and todetermine whether such updated location estimate data should or shouldnot be communicated, or pushed, to the public safety answering point 104upon occurrences of a triggering event.

The mobile switching center 108 (sometimes referred to herein as “MSC108”) comprises a processing unit, a data storage device storingsoftware program instructions executable by the processing unit, memory,and voice and data communication interfaces. The mobile switching center108 is adapted to communicatively connect to the gateway mobilecommunication center 106 as described above, through bi-directional datacommunication link 118, during the handling of an emergency call from amobile station 102. The mobile switching center 108 is also adapted tocommunicatively connect to the base station controller 110, via theMSC's voice and data communication interfaces and respectivebi-directional voice and data communication links 120, 122, during thehandling of the emergency call in order to bi-directionally communicatespeech, sounds, messages, signals, and data with the base stationcontroller 110. Additionally, the mobile switching center 108 isconfigured to communicatively connect to the public safety answeringpoint 104, through bi-directional voice communication trunks 124 anddata communication link 126, during the handling of the emergency callfor the bi-directional communication of speech, sounds, and data betweenthe mobile switching center 108 and public safety answering point 104.

During operation, the processing unit of the mobile switching center 108executes the MSC's software program instructions such that the mobileswitching center 108 is operable to perform according to the methodsdescribed herein and to bi-directionally communicate speech, sounds,messages, signals, and data between the base station controller 110,public safety answering point 104, and gateway mobile location center106 as appropriate. More particularly, the mobile switching center 108is operable to: receive a message from the base station controller 110requesting a voice communication path 140 between the calling mobilestation 102 and the appropriate public safety answering point 104 (i.e.,corresponding to an emergency call); communicate an initial message forthe emergency call to the gateway mobile location center 106 includingthe emergency services routing digits and the phone number for themobile station 102 from which the emergency call originated; receive aresponse to the initial message from the gateway mobile location center106 including an emergency services routing key for the emergency call;set up a voice communication path 140 (including, for example, voicecommunication trunks 124, voice communication links 120, 128, and voicecommunication channels 136) for the emergency call between the mobilestation 102 and the public safety answering point 104 in response toreceiving the emergency services routing key; and, communicate theemergency service routing key for the emergency call to the publicsafety answering point 104.

The mobile switching center 108 is further operable during an emergencycall to: automatically communicate a message to the base stationcontroller 110 requesting an initial location estimate for the callingmobile station 102; receive a message from the base station controller110 including an initial location estimate for the mobile station 102 inresponse thereto; communicate a message including an initial locationestimate for the mobile station 102 to the gateway mobile locationcenter 106; and, receive a message from the gateway mobile locationcenter 106 acknowledging receipt of the initial location estimate.Additionally, the mobile switching center 108 is further operable duringan emergency call to: receive messages from the gateway mobile locationcenter 106 requesting updated location estimates for the mobile station102; communicate messages to the gateway mobile location center 106including such updated location estimates for the mobile station 102 inresponse thereto; communicate messages to the base station controller110 requesting such updated location estimates for the mobile station102; and, in response thereto, receive messages from the base stationcontroller 110 including such requested updated location estimates.During an emergency call, the mobile switching center 108 is stillfurther operable to: receive messages from the base station controller110 indicating that the base station controller 110 has detectedmovement of the mobile station 102 and including information or datacomprising the phone number for the calling mobile station 102, theidentifier for the mobile switching center 108, and the globalidentifier for the cell or sector, as the case may be, in which themobile station 102 is present; responsive thereto, communicate messagesto the base station controller 110 acknowledging receipt of suchinformation; communicate messages to the gateway mobile location center106 including such information; and, receive messages from the gatewaymobile location center 106 acknowledging the receipt of suchinformation.

The base station controller 110 (sometimes referred to herein as “BSC110”) comprises a processing unit, a data storage device storingsoftware program instructions executable by the processing unit, memory,and appropriate voice and data communication interfaces. The basestation controller 110 is adapted to communicatively connect to themobile switching center 108 as described above, through bi-directionalvoice and data communication links 120, 122, during the handling of anemergency call from a mobile station 102. Also, the base stationcontroller 110 is adapted to communicatively connect to transceivers 114via the BSC's voice and data communication interfaces and respectivebi-directional voice and data communication links 128, 130.Additionally, the base station controller 110 is configured to connectto the serving mobile location center 112, via data communication link132, for the bi-directional communication of data therewith. Typically,data communication link 132 includes an SS7 switch.

During operation, the processing unit of the base station controller 110executes the BSC's software program instructions such that the basestation controller 110 is operable to perform according to the methodsdescribed herein and to bi-directionally communicate speech, sounds,messages, signals, and data with the mobile switching center 108 andtransceivers 114 through respective bi-directional voice communicationlinks 120, 128 and bi-directional data communication links 122, 130. Thebase station controller 110 is also operable to bi-directionallycommunicate messages, signals, and data with the serving mobile locationcenter 112 via data communication link 132. More particularly, the basestation controller 110 is operable to: receive a message from a callingmobile station 102 requesting a voice communication path 140 between themobile station 102 and the appropriate public safety answering point 104(i.e., corresponding to an emergency call); responsive thereto,communicate a message to the mobile switching center 108 requesting suchvoice communication path 140; receive a message from the mobileswitching center 108 requesting an initial location estimate for themobile station 102; communicate a message to the mobile switching center108 including such initial location estimate for the mobile station 102in response thereto; communicate a message to the serving mobilelocation center 112 requesting such initial location estimate; and, inresponse, receive a message from the serving mobile location center 112including such initial location estimate.

The base station controller 110 is further operable during an emergencycall to: receive messages from the mobile switching center 108requesting updated location estimates for the mobile station 102;communicate messages to the mobile switching center 108 including suchupdated location estimates for the mobile station 102 in responsethereto; communicate messages to the serving mobile location center 112requesting such updated location estimates for the mobile station 102;and, in response thereto, receive messages from the serving mobilelocation center 112 including such requested updated location estimates.During an emergency call, the base station controller 110 is stillfurther operable to: detect handovers, if any, of the emergency callbetween cells or sectors, as the case may be; communicate messages tothe mobile switching center 108 indicating that the base stationcontroller 110 has detected handovers (e.g., movement) of the mobilestation 102 and including information or data comprising the phonenumber for the calling mobile station 102, the identifier for the mobileswitching center 108, and the global identifier for the cell or sector,as the case may be, in which the mobile station 102 is present; and,receive messages from the mobile switching center 108 acknowledgingreceipt of such indicating messages and information in response thereto.

The serving mobile location center 112 (sometimes referred to herein as“SMLC 112”) comprises a processing unit, a data storage device storingsoftware program instructions executable by the processing unit, memory,and appropriate data communication interfaces. The serving mobilelocation center 112 is adapted to communicatively connect to the basestation controller 110 as described above through bi-directional datacommunication link 132 during the handling of an emergency call from amobile station 102. The processing unit of the serving mobile locationcenter 112 executes the SMLC's software program instructions duringoperation such that the serving mobile location center 112 is operableto perform according to the methods described herein and tobi-directionally communicate messages, signals, and data with basestation controller 110 through bi-directional data communication link132. More particularly, the serving mobile location center 112 isoperable to: receive messages from the base station controller 110requesting initial and updated location estimates for the mobile station102; and in response thereto, determine initial and updated locationestimates for the mobile station 102 and communicate messages includingsame to the base station controller 110. According to the exemplaryembodiments of the present invention, the serving mobile location center112 uses data representative of the then present location of the mobilestation 102 (e.g., collected from one or more location measurement units(“LMUs”)) and triangulation techniques in order to determine initial andupdated location estimates for the mobile station 102. However, itshould be understood that other data, equipment, and/or methods might beemployed within the scope of the present invention to determine initialand updated location estimates of the mobile station 102.

Each transceiver 114 generally includes a transmitter, receiver, andantenna for bi-directionally communicating voice and data signals withthe mobile station 102 via respective wireless bi-directional voice anddata communication channels 136, 138. Typically, each transceiver 114 isassociated with a particular cell or sector, as the case may be, and hasits antenna mounted to a tower, building, or other structure appropriateto enable the antenna to service the cell or sector.

FIG. 2 displays a flowchart representation of a method for handling anemergency call from a mobile station 102 and for automatically providingupdated location estimates for the mobile station 102 to a public safetyanswering point 104 of an emergency services provider during theemergency call 200 (sometimes referred to herein as “method 200”) inaccordance with a first exemplary embodiment of the present invention.When operated according to method 200, the wireless network 100automatically provides, or pushes, such updated location estimateinformation to the public safety answering point 104 (via W-ALI 105 andbi-directional communication links 116, 117) upon the occurrence of atriggering event generated within the wireless network 100, which in thefirst exemplary embodiment, comprises a countdown timer reaching zeroafter counting down from an initial amount of time. Notably, theprovision, or communication, of such updated location estimateinformation is made absent any request from the public safety answeringpoint 104 (or, for that matter, absent any request from outside of thewireless network 100) and is, generally, made on a periodic basis duringan emergency call as the countdown timer is reinitialized after eachcommunication of updated location estimate information to the publicsafety answering point 104.

After starting at step 202, method 200 advances to step 204 where thewireless network 100 receives a connection management service requestmessage 600 (see FIG. 6) from a mobile station 102 to establish anemergency call between the mobile station 102 and an appropriate publicsafety answering point 104 in response to a user of the mobile station102 (i.e., a caller) making an emergency call. More particularly and asillustrated by FIGS. 1 and 6, the base station controller 110 of thewireless network 100 receives the connection management service requestmessage 600 from the mobile station 102 via the transceiver(s) 114 thatprovide wireless communication services for the wireless communicationcell or sector in which the mobile station 102 is then present. Next,method 200 proceeds to step 206 thereof where the wireless network 100establishes a voice communication path 140 between the appropriatepublic safety answering point 104 and the mobile station 102 to enablevoice communication between a dispatcher at the public safety answeringpoint 104 and the caller. In accordance with the exemplary embodimentsdescribed herein, set up of the voice communication path 140 isinitiated by the base station controller 110 messaging the mobileswitching center 108 and is subsequently completed by the mobileswitching center 108 connecting voice communication trunks 124, voicecommunication links 120, 128, and wireless voice communication channel136. A more detailed description of the steps and intra-networkmessaging used to accomplish establishment of the voice communicationpath are included below with respect to FIGS. 3 and 6.

Proceeding to step 208, the wireless network 100 determines andcommunicates an initial location estimate for the mobile station 102 tothe public safety answering point 104. Typically, the initial locationestimate is provided to the public safety answering point 104 (via W-ALI105 and bi-directional communication links 116, 117) by the wirelessnetwork 100 in response to the wireless network 104 (and, morespecifically, the gateway mobile location center 106) receiving amessage from the public safety answering point 104 (via W-ALI 105 andbi-directional communication links 116, 117) requesting that thewireless network 100 send it an initial location estimate for the mobilestation 102. In accordance with the exemplary embodiments, the initiallocation estimate is usually determined through the use of triangulationtechniques using data collected by the serving mobile location center112. Generally, the initial location estimate comprises datarepresenting the estimated latitude and longitude of the location of themobile station 102 when the caller made the emergency call. The stepsassociated with the determination and communication of the initiallocation estimate for the mobile station 102 are described more fullybelow with reference to FIG. 4. It should be noted that the initiallocation estimate might be determined within the scope of the presentinvention, however, through the use of other data, equipment, and/ormethods.

Continuing at step 210 of method 200, the wireless network 100 (and,more specifically, the gateway mobile location center 106) initializes acountdown timer to a pre-determined period of time and starts thecountdown timer counting down toward zero. The pre-determined period oftime represents the amount of time that will elapse between theautomatic determination and communication, or pushing, of consecutiveupdated location estimates for the then current respective locations ofthe mobile station 102 to the public safety answering point 104. Itshould be noted that the wireless network 100 might be configured suchthat a different pre-determined period of time is used for triggeringthe automatic determination and communication of mobile station updatedlocation estimates for each different public safety answering point 104with which the wireless network 100 communicates. The pre-determinedperiod of time for use with a particular public safety answering point104 may be selected to: maximize the currency of the estimated locationof a mobile station 102; minimize the impact on or use of networkresources; adhere to constraints and/or requirements imposed by hardwareand/or software at the public safety answering point 104; meetrespective public safety organizations' and/or dispatchers' preferencesfor the currency of the estimated location of a mobile station 102;and/or optimize any combination of the foregoing. It should beunderstood that the scope of the present invention comprises the use ofhardware and software timers, count up and countdown timers, and timersthat are configured to count between non-zero starting and endingvalues.

At step 212, the wireless network 100 (and, more specifically, thegateway mobile location center 106) determines whether the countdowntimer has reached zero (i.e., expired) after counting down thepre-determined amount of time to which it was initialized at step 210.If the countdown timer has not reached zero, then no triggering eventhas occurred and the gateway mobile location center 106 loops back tostep 212 to again determine whether the countdown timer has expired.Alternatively, if the countdown timer has reached zero, a triggeringevent (i.e., expiration of the tinier) has occurred and the gatewaymobile location center 106 advances to step 214 of method 200 where thewireless network 100 determines and communicates an updated locationestimate for the mobile station 102 to the public safety answering point104 via the gateway mobile location center 106, W-ALI 105, and datacommunication links 116, 117. The provision of such updated locationestimate is performed, generally, in accordance with the steps of method500 described below with respect to FIG. 5.

It should be remembered that the provision, communication, or pushing ofupdated location estimate information to the public safety answeringpoint 104 is made absent any request from the public safety answeringpoint 104 for such information. It should be further remembered thatsuch provision, communication, or pushing of updated location estimateinformation for the mobile station 102 continues according to methods200, 500 until the emergency call is disconnected, dropped, orterminated by the caller, by a dispatcher of the public safetyorganization, or by the occurrence of another event.

FIG. 3 displays a flowchart representation of a method for establishinga voice communication path 300 between a mobile station 102 requestingan emergency call and a public safety answering point 104 of anemergency services provider in accordance with a first exemplaryembodiment of the present invention. After starting at step 302 of themethod for establishing a voice communication path 300 (sometimesreferred to herein as “method 300”), the wireless network 100 initiatesset up of the emergency call with the base station controller 110communicating a message 602 to the mobile switching center 108 throughdata communication link 122 at step 304. Generally, the message 602comprises a connection management service request (“CM Service Request”)message as illustrated in FIG. 6. Upon receiving message 602 and as partof initiating set up of the emergency call at step 304, the mobileswitching center 108 subsequently communicates a message 604 to thegateway mobile location center 106 via data communication link 118. Asdisplayed in FIG. 6, the message 604, typically, comprises an integratedservices user part initial address (“ISUP JAM”) message and includesinformation such as (a) the emergency services routing digits (“ESRD”)associated with the cell site in which the mobile station 102 waspresent when requesting the emergency call and (b) the call back numberfor the mobile station 102.

After receiving message 604 from the mobile switching center 108, thegateway mobile location center 106 assigns an emergency services routingkey (“ESRK”) to the emergency call at step 306. The emergency servicesrouting key uniquely identifies the emergency call and is used incommunications with the public safety answering point 104 as describedbelow. The gateway mobile location center 106 then, at step 308,communicates a message 606 to the mobile switching center 108, via datacommunication link 118, providing the assigned emergency service routingkey and directing the mobile switching center 108 to set up a voicecommunication path 140 between the public safety answering point 104 andthe mobile station 102. The message 606, generally, comprises anintegrated services use part initial address (“ISUP IAM”) message thatincludes the assigned emergency service routing key (see FIG. 6). Uponreceiving message 606 from the gateway mobile location center 106, themobile switching center 108 sets up a voice communication path 140between the public safety answering point 104 and the mobile station 102at step 310. Then, at step 312, the mobile switching center 108communicates the emergency services routing key to the public safetyanswering point 104 through data communication link 126. Once theemergency services routing key has been communicated to the publicsafety answering point 104, operation of the wireless network 100 inaccordance with method 300 ends at step 314.

FIG. 4 displays a flowchart representation of a method for determiningand communicating an initial location estimate for a mobile station 102to a public safety answering point 104 of an emergency services providerin accordance with the first exemplary embodiment of the presentinvention. As described briefly above with respect to FIG. 2, thewireless network 100 determines and communicates an initial locationestimate for the mobile station 102 to the public safety answering point104 after a voice communication path 140 is established for an emergencycall placed from the mobile station 102. To do so, the wireless network100 operates in accordance with the method of determining andcommunicating an initial location estimate 400 (sometimes referred toherein as “method 400”) described below and automatically determines aninitial location estimate for the mobile station 102 prior to receivinga request for same from the public safety answering point 104 handlingthe emergency call.

After starting operation according to method 400 at step 402, thewireless network 100 automatically initiates the determination of aninitial location estimate for the mobile station 102 at step 404 byinternally communicating a series of messages 608, 610. First, themobile switching center 108 communicates a message 608 to the basestation controller 110 through data communication link 122 to requestthe performance of a location determination for the mobile station 102.Generally, message 608 comprises a perform location request(“Perf_Loc_REQ”) message as illustrated in FIG. 6. Then, in response toreceiving message 608, the base station controller 110 communicates amessage 610 via data communication link 132 to the servicing mobilelocation center 112 to request that it determine the location of themobile station 102. Similar to message 608 described above, message 610also, typically, comprises a perform location request (“Perf_Loc_REQ”)message (see FIG. 6).

Continuing at step 406 of method 400, the servicing mobile locationcenter 112 communicates and receives messages 612 (see FIG. 6) withvarious location measurement units appropriate and necessary todetermine an initial location estimate for the mobile station 102.Generally, in accordance with the exemplary embodiments, the initiallocation estimate is made using triangulation techniques (e.g., known toone of ordinary skill in the art) and data collected by the servicingmobile location center 112 from the location measurement units viamessages 612 that pertains to the initial location of the mobile station102. The initial location estimate is represented by location estimatedata comprising, typically, an estimated latitude and longitude for themobile station 102 and a statistically-generated number corresponding tothe number of meters around the intersection of the estimated latitudeand longitude in which there is a pre-determined percentage ofconfidence that the mobile station 102 is present. It should beremembered that other equipment, messaging, and methods (i.e., otherthan triangulation) might be employed by the wireless network 100 withinthe scope of the present invention to determine the initial locationestimate.

Once an initial location estimate has been determined for the mobilestation 102, the initial location estimate is returned to the mobileswitching center 108, at step 408, through a series of messages 614, 616communicated internally within the wireless network 100. First, theservicing mobile location center 112 communicates a message 614, viadata communication link 132, to the base station controller 110including the location estimate data corresponding to the initiallocation estimate for the mobile station 102 when the emergency call wasrequested by the mobile station 102. Generally, message 614 comprises aperform location response (“Perf_Loc_Resp”) message (see FIG. 6).Subsequently, in response to receiving message 614 from the servicingmobile location center 112, the base station controller 110 communicatesa message 616 to the mobile switching center 108 through datacommunication link 122. Message 616, similar to message 614, typicallycomprises a perform location response (“Perf_Loc_Resp”) message (seeFIG. 6) including the location estimate data corresponding to theinitial location estimate for the mobile station 102 when the emergencycall was requested by the mobile station 102. After the locationestimate data has been received, the mobile switching center 108communicates a message 618 to the gateway mobile location center 106 viadata communication link 118 including the location estimate data. Asillustrated in FIG. 6, the message 618 is, generally, in the form of a“Sub_Loc_Report” message. Upon receiving message 618 from the mobileswitching center 108, the gateway mobile location center 106acknowledges the receipt of the initial location estimate from themobile switching center 108 by communicating an acknowledgement message620 thereto through data communication link 118. The acknowledgementmessage 620, typically, comprises a “Sub Loc_Report_Ack” message asdisplayed in FIG. 6.

After the gateway mobile location center 106 receives the initiallocation estimate and at step 410, the gateway mobile location center106 communicates a message 624 to the W-ALI 105 via data communicationlink 116 providing the initial location estimate to the W-ALI 105.Generally, the message 624 is communicated by the gateway mobilelocation center 106 to the W-ALI 105 in the form of a “ESPOSRESP”message (see FIG. 6) that includes (a) the emergency services routingdigits, (b) the callback number of the mobile station 102, and (c) thelocation estimate data representing the initial location estimate forthe mobile station 102. Then, at step 412, the W-ALI 105 determineswhether it has received a request for an initial location estimate forthe mobile station 102 from the public safety answering point 104handling the emergency call. Generally, such request is in the form ofan emergency services position request (“ESPOSREQ”) message 622 (seeFIG. 6) communicated by the public safety answering point 104 to theW-ALI 105 via data communication link 117. The message 622 includes theemergency services routing key uniquely associated with the emergencycall in order to enable the W-ALI 105 to identify the emergency callfrom all other emergency calls possibly being handled by the W-ALI 105.

If at step 412, the W-ALI 105 determines that it has not received arequest for an initial location estimate, method 400 loops back to step412 to continue waiting for such a request. Alternatively, if at step412, the W-ALI 105 determines that it has received a request for aninitial location estimate for the mobile station 102 from the publicsafety answering point 104, the W-ALI 105 further communicates message624 to the public safety answering point 104 through data communicationlink 117 at step 414, thereby providing the initial location estimatefor the mobile station 102 to the public safety answering point 104.Method 400 then ends at step 416.

FIG. 5 displays a flowchart representation of a method for determiningand communicating an updated location estimate for a mobile station 102to a public safety answering point 104 of an emergency services providerin accordance with the first exemplary embodiment of the presentinvention. As described briefly above with respect to FIG. 2, thewireless network 100 automatically determines and communicates updatedlocation estimate information for the mobile station 102 to the publicsafety answering point 104 during the emergency call between the mobilestation 102 and public safety answering point 104 upon the occurrence ofan internally generated triggering event. Operating in accordance withthe method for determining and communicating an updated locationestimate 500 (sometimes referred to herein as “method 500”), thewireless network 100 “pushes” the updated location estimate informationfor the mobile station 102 to the public safety answering point 104(i.e., via bi-directional communication links 116, 117 and W-ALI 105which further communicates, or “pushes”, the updated location estimateinformation) handling the emergency call absent a request for suchinformation from the public safety answering point 104.

After starting at step 502 of method 500, the wireless network 100initiates the determination of an updated location estimate for themobile station 102 at step 504 by internally communicating a series ofmessages 700, 702, 704. Initially, the gateway mobile location center106 communicates a message 700 to the mobile switching center 108, viadata communication link 118, to request an updated locationdetermination for the mobile station 102. Message 700 generallycomprises a provide location request (“Prov_Sub_Loc”) message asdisplayed in FIG. 7. Then, upon receiving message 700, the mobileswitching center 108 communicates message 702 to the base stationcontroller 110 through data communication link 122 to request theperformance of a location determination for the mobile station 102.Generally, as illustrated in FIG. 7, message 702 comprises a performlocation request (“Perf_Loc_REQ”) message. After receiving message 702,the base station controller 110 communicates message 704 to the servingmobile location center 112, via data communication link 132, requestingthat the serving mobile location center 112 determine the currentlocation of the mobile station 102. Similar to message 702 describedabove, message 704 also, typically, comprises a perform location request(“Perf_Loc_REQ”) message (see FIG. 7).

Proceeding to step 506, the servicing mobile location center 112determines an updated location estimate for the mobile station 102.Similar to the initial location estimate and according to the firstexemplary embodiment, the updated location estimate is made usingtriangulation techniques (e.g., known to one of ordinary skill in theart) and data collected by the servicing mobile location center 112 fromvarious location measurement units, via the communication of messages706, pertaining to the mobile station's then current location. Theupdated location estimate is also represented by location estimate datacomprising, typically, an estimated latitude and longitude for themobile station 102 and a statistically-generated number corresponding tothe number of meters around the intersection of the estimated latitudeand longitude in which there is a per-determined percentage ofconfidence that the mobile station 102 is present. It should beremembered that the scope of the present invention further includes theuse of other equipment, data, and/or methods for determining the presentlocation of the mobile station 102.

Upon determining an updated location estimate for the mobile station102, the updated location estimate is returned, at step 508, to thegateway mobile location center 106 via a series of messages 708, 710,712 communicated internally within the wireless network 100. First, theservicing mobile location center 112 communicates message 708 to thebase station controller 110 through data communication link 132. Message708 includes location estimate data corresponding to the updatedlocation estimate for the mobile station 102. Generally, message 708comprises a perform location response (“Perf_Loc_Resp”) message (seeFIG. 7). Then, the base station controller 110 communicates a message710 to the mobile switching center 108 through data communication link122 in response to receiving message 708 from the servicing mobilelocation center 112. Similar to message 708, message 710 typicallycomprises a perform location response (“Perf_Loc_Resp”) message (seeFIG. 7) including the location estimate data corresponding to theupdated location estimate for the mobile station 102. Next, afterreceiving message 710, the mobile switching center 108 communicates amessage 712 to the gateway mobile location center 106 via datacommunication link 118 including the location estimate datacorresponding to the updated location estimate. As illustrated in FIG.7, the message 712 is, generally, in the form of a “Prov_Sub_Loc_Ack”message.

At step 510 of method 500, the wireless network 100 (and, morespecifically, the gateway mobile location center 106) communicates amessage 714 including the updated location estimate for the mobilestation 102 to the public safety answering point 104. Such communicationis, generally, accomplished by the communication of message 714 to theW-ALI 105 via data communication link 116, followed by the W-ALI 105then communicating message 714 on to the public safety answering point104 through data communication link 117. The message 714 generallyincludes the emergency services routing key and the location estimatedata corresponding to the updated location estimate. Inclusion of theemergency services routing key serves to inform the public safetyanswering point 104 as to which emergency call the update locationestimate corresponds. This is important since the public safetyanswering point 104 may be then handling a plurality of emergency callsand since the updated location estimate is provided without a requestfrom the public safety answering point 104. Typically, message 714comprises an emergency services position push (“ESPOSPUSH”) message.Because the updated location estimate has not requested by the publicsafety answering point 104, such communication of the updated locationestimate to the public safety answering point 104 is referred to as a“pushing” of the updated location estimate.

In response to receiving the updated location estimate pushed to thepublic safety answering point 104 by the communication of message 714,the public safety answering point 104 communicates a message 716 to thewireless network 100 through W-ALI 105 and bi-directional communicationlinks 116, 117 acknowledging receipt of the updated location estimate.The wireless network 100 (and, more particularly, the gateway mobilelocation center 106) receives message 716 at step 512 of method 500.Generally, as displayed in FIG. 7, message 716 comprises an emergencyservices position push acknowledge (“ESPOSPUSH_ACK”) message. Afterreceiving message 716 acknowledging receipt of the updated locationestimate for mobile station 102, the wireless network 100 ends operationaccording to method 500 at step 514.

FIGS. 8A-8B display a flowchart representation of a method for handlingan emergency call from a mobile station 102 and for automaticallyproviding updated location estimates for the mobile station 102 to apublic safety answering point 104 of an emergency services providerduring the emergency call in accordance with a second exemplaryembodiment of the present invention. When operated according to themethod for handling an emergency call from a mobile station 102 and forautomatically providing updated location estimates 800 (sometimesreferred to herein as “method 800”), the wireless network 100automatically provides, or pushes, such updated location estimateinformation to the public safety answering point 104 (via W-ALI 105 andbi-directional data communication links 116, 117) upon the occurrence ofa triggering event generated within the wireless network 100 and thesatisfaction of certain trigger-related conditions. The triggering eventgenerally comprises the detection of movement of the mobile station 102and the trigger-related conditions generally relate to whether a minimumperiod of time has elapsed since the previous pushing of updatedlocation estimate information to the public safety answering point 104and to whether pushing of the updated location estimate information isenabled for the public safety answering point 104 handling the emergencycall. Notably, as in the first exemplary embodiment, the automaticprovision or communication of such updated location estimate informationis made absent any request from the public safety answering point 104(or, for that matter, absent any request from outside of the wirelessnetwork 100).

After starting at step 802, method 800 advances to step 804 where thewireless network 100 receives a message 600 (see FIG. 6) from a mobilestation 102 requesting that the wireless network 100 establish anemergency call between the mobile station 102 and an appropriate publicsafety answering point 104 in response to a user of the mobile station102 (i.e., a caller) making an emergency call. Generally, message 600comprises a connection management service request message (see FIG. 6)that is received by one or more transceiver(s) 114 and communicated, viadata communication link 130 and wireless bi-directional datacommunication channel 138, to a base station controller 110 thatprovides wireless communication services for the wireless communicationcell(s) in which the mobile station 102 is then present. Upon receivingmessage 600, at step 806, the wireless network 100 establishes a voicecommunication path 140 between the appropriate public safety answeringpoint 104 and the mobile station 102 in order to enable voicecommunication between a dispatcher at the public safety answering point104 and the user of the mobile station 102. Set up of the voicecommunication path 140 is, according to the exemplary embodiments of thepresent invention and as described in more detail above with respect tomethod 300 and FIG. 3, initiated by the base station controller 110messaging the mobile switching center 108 and subsequently completed bythe mobile switching center 108 connecting voice communication links120, 128, wireless bi-directional voice communication channels 136, andvoice communication trunks 124.

Continuing at step 808 of method 800, the wireless network 100determines and communicates an initial location estimate for the mobilestation 102 to the public safety answering point 104 via the W-ALI 105and data communication links 116, 117. Generally, the initial locationestimate is automatically determined by the wireless network 100 afterset up of the voice communication path 140 between the mobile station102 and the public safety answering point 104 and is communicated to thepublic safety answering point 104 in response to the W-ALI 105 receivinga message from the public safety answering point 104 requesting aninitial location estimate for the mobile station 102. Similar to thefirst exemplary embodiment, the initial location estimate is typicallydetermined through the use of triangulation techniques using datacollected from various location measurement units, but may be determinedthrough the use of other data and methods. Also similarly, the initiallocation estimate comprises data representing the estimated latitude andlongitude of the location of the mobile station 102 when the caller madethe emergency call. The particular steps associated with thedetermination and communication of the initial location estimate for themobile station 102 to the public safety answering point 104 have beenmore fully described above with respect to method 400 and FIG. 4.

Next, at step 810 of method 800, the wireless network 100 (and, morespecifically, the gateway mobile location center 106) initializes acount up timer to zero such that during operation, the timer countsupward toward a pre-determined threshold value described more fullybelow. After initializing the timer and at step 812, the gateway mobilelocation center 106 checks to see if a handover of the emergency call toa new cell or sector (i.e., depending on the particular implementationof the present invention) has been detected by other parts of thewireless network 100 due to movement of the mobile station 102 into suchnew cell or new sector. The detection of such handover (and, hence,movement) constitutes the occurrence of a triggering event that triggersthe wireless network's automatic pushing of an updated location estimatefor the mobile station 102 to the public safety answering point 104 thatis not in response to the receipt of a request for an updated locationestimate.

The detection of emergency call handover and mobile station movement ismade when the base station controller 110 learns that the emergency callhas been handed over to a new cell or new sector, as the case may be. Inresponse to learning of the handover, the base station controller 110communicates a message 900 (see FIG. 9) to the mobile switching center108 indicating that the mobile station 102 has moved to a new cell ornew sector. According to the second exemplary embodiment, message 900comprises an emergency call location update message and includes datarepresentative of the mobile station's international ISDN number(“MSISDN”), a mobile switching center identifier (“MSCID”) that uniquelyidentifies the mobile switching center 108 handling the emergency call,and a cell global identifier (“CGI”) that uniquely identifies the cellin which the mobile station 102 is then present. Upon receiving message900, the mobile switching center 108 responds by communicating message902 (see FIG. 9) to the base station controller 110 to indicate thatmessage 900 has been received. Message 902 typically comprises anemergency call location update acknowledge message. Upon receivingmessage 902, the mobile switching center 108 also communicates a message904 (see FIG. 9) to the gateway mobile location center 106 indicatingthat the mobile station 102 has moved to a new cell or new sector.Responsive to its receipt of message 904, the gateway mobile locationcenter 106 communicates a message 906 (see FIG. 9) to the mobileswitching center 108 acknowledging the receipt of message 904. Similarto messages 900, 902 received and sent by the mobile switching center108, messages 904, 906 generally comprise respective emergency calllocation update and emergency call location update acknowledge messages.

Continuing in accordance with method 800, if the gateway mobile locationcenter 106 determines that handover of the emergency call and movementof the mobile station 102 into a new cell or new sector has not beendetected by the wireless network 100 (e.g., because the gateway mobilelocation center 106 has not received message 904 from the mobileswitching center 108) at step 812, then the gateway mobile locationcenter 106 loops back to step 812 to once again check to see whethersuch handover of the emergency call and movement of the mobile station102 has been detected. Alternatively, at step 812, if the gateway mobilelocation center 106 determines that handover of the emergency call andmovement of the mobile station 102 has been detected (e.g., because thegateway mobile location center 106 has received message 904 from themobile switching center 108), the gateway mobile location center 106advances to step 814 of method 800 where it ascertains whether thecurrent tinier value is greater than a pre-determined threshold value.Notably, the pre-determined threshold value constitutes a minimum periodof time that must transpire between the automatic provision ofconsecutive updated location estimates for the mobile station 102 to thepublic safety answering point 104 and is selected to allow the provisionof a sufficient number of updated location estimates to the publicsafety answering point 104 while avoiding the overly frequent provisionof updated location estimates to the public safety answering point 104that might tend to unnecessarily tie up network resources. Such overlyfrequent provision of updated location estimates might otherwise occur,for instance, if the mobile station 102 is detected moving in and out ofcells or sectors along a boundary between cells or sectors during abrief period of time.

If the gateway mobile location center 106 ascertains that the currenttimer value is less than or equal to the pre-determined threshold valueat step 814, it is presumed that the mobile station 102 may, indeed, bemoving rapidly in and out of cells or sectors along a boundary betweencells or sectors and, hence, that the provision of an updated locationestimate to the public safety answering point 104 is not appropriate atthe present time because such movement is insubstantial. Therefore, thegateway mobile location center 106 loops back to step 812 to once againcheck to see whether handover of the emergency call and movement of themobile station 102 into a new cell or new sector has been detected bythe wireless network 100. If, alternatively, the gateway mobile locationcenter 106 ascertains that the current timer value is greater than thepre-determined threshold value at step 814, it is presumed that themobile station 102 is not moving rapidly in and out of cells or sectorsalong a boundary between cells or sectors and that the provision of anupdated location estimate for the mobile station 102 to the publicsafety answering point 104 is appropriate and/or warranted because suchmovement is substantial. Based upon such presumption, operation of thewireless network 100 advances to step 816 of method 800 described below.

At step 816, the gateway mobile location center 106 checks to seewhether the automatic provision of updated location estimates to thepublic safety answering point 104 that are not in response to thereceipt of a request for same from the public safety answering point 104(or, for that matter, from outside of the wireless network 100) has beenenabled for the public safety answering point 104. In other words, thegateway mobile location center 106 determines whether the wirelessnetwork 100 is to automatically “push” non-requested updated locationestimates for the mobile station 102 to the public safety answeringpoint 104 during an emergency call. The gateway mobile location center106 makes such determination by retrieving enablement data associatedwith the public safety answering point 106 handling the emergency callfrom the GMLC's data storage device and evaluating the retrievedenablement data. If, after performing its evaluation, the gateway mobilelocation center 106 determines that the automatic “pushing” of suchnon-requested updated location estimates is not enabled for the publicsafety answering point 104 handling the emergency call, then the gatewaymobile location center 106 loops back to step 810 to once againinitialize the count up timer to zero. Alternatively, if the gatewaymobile location center 106 determines that the automatic “pushing” ofsuch non-requested updated location estimates is enabled for the publicsafety answering point 104 handling the emergency call, then the gatewaymobile location center 106 advances to step 818 of method 800 where itinitiates the automatic provision of an updated location estimate forthe mobile station 102 to the public safety answering point 104. Thewireless network 100 then proceeds to provide such updated locationestimate by operating in accordance with method 500 described above withreference to FIG. 5. Once an updated location estimate has beenprovided, or “pushed”, to the public safety answering point 104,operation of the wireless network 100 continues at step 810 where thecount up timer is once again initialized to zero. Upon termination ofthe emergency call, the wireless network 100 ceases operation inaccordance with method 800.

It should be noted that the scope of the present invention compriseswireless networks 100 configured such that the same or a differentpre-determined threshold value or minimum period of time between theautomatic provision of consecutive updated location estimates for themobile station 102 is used as a trigger-related condition forcontrolling the automatic determination and communication of mobilestation updated location estimates for each different public safetyanswering point 104 with which the wireless network 100 communicates. Itshould also be noted that the scope of the present invention compriseswireless networks 100 using hardware and/or software timers, count upand/or countdown timers, and timers that are configured to count betweennon-zero starting and ending values.

Whereas this invention has been described in detail with particularreference to exemplary embodiments and variations thereof, it isunderstood that other variations and modifications can be effectedwithin the scope and spirit of the invention, as described herein beforeand as defined in the appended claims.

The invention claimed is:
 1. A system, comprising: a processor; acomputer-readable storage medium comprising computer-executableinstructions that, when executed by the processor, cause the processorto perform operations, for processing an emergency call between awireless communication device and a public safety answering point,comprising: detecting whether a triggering event associated with theemergency call has occurred, wherein the triggering event includeshandover of the emergency call from a first subdivision of the wirelesscommunication network to a second subdivision of the wirelesscommunication network; determining, in response to detecting that thetriggering event has occurred, whether a triggering condition associatedwith the emergency call is satisfied, wherein the triggering conditionincludes a current value of a previously-initiated count-up timer beinggreater than a pre-determined threshold value; and determining, inresponse to determining that the triggering condition is satisfied,whether an automatic provision of updated location estimates feature hasbeen enabled for the public safety answering point.
 2. The system ofclaim 1, wherein: the operation of determining whether the triggeringcondition is satisfied is performed in a determination operation; andthe operations further comprise returning, in response to determiningthat the triggering condition is not satisfied, to the determiningoperation.
 3. The system of claim 1, wherein: the operations furthercomprise initializing the count-up timer; and the operation of detectingwhether the triggering event has occurred is performed afterinitializing the count-up timer.
 4. The system of claim 1, wherein theautomatic provision of updated location estimates feature, when enabled,provides for provisioning of updated location estimates to the publicsafety answering point automatically and not in response to a requestfor updated location estimate.
 5. The system of claim 1, wherein theoperations further comprise: initializing a count-up timer in aninitializing operation; and returning, in response to determining thatthe automatic provision of updated location estimates feature has notbeen enabled for the public safety answering point, to the initializingoperation.
 6. The system of claim 1, wherein the operations furthercomprise performing, in response to determining that the automaticprovision of updated location estimates feature has been enabled for thepublic safety answering point, additional operations comprising:obtaining updated location information for the wireless communicationdevice; and transmitting the updated location information to the publicsafety answering point.
 7. The system of claim 1, wherein thepre-determined threshold value corresponds to (i) a time period and (ii)whether movement of the wireless communication device is substantial orunsubstantial.
 8. The system of claim 1, wherein the pre-determinedthreshold value corresponds to a time period related to a desired timefrequency with which position updates should be provided to the publicsafety answering point.
 9. The system of claim 1, wherein thepre-determined threshold value corresponds to a value distinguishingbetween: (I) insubstantial movement of the wireless communicationdevice; and (II) substantial movement of the wireless communicationdevice.
 10. A system, comprising: a processor; and a computer-readablestorage medium comprising computer-executable instructions that, whenexecuted by the processor, cause the processor to perform operations,for processing an emergency call between a wireless communication deviceand a public safety answering point, comprising: detecting, by acomponent of a wireless communication network, whether a triggeringevent associated with the emergency call has occurred, wherein thetriggering event includes handover of the emergency call from a firstsubdivision of the wireless communication network to a secondsubdivision of the wireless communication network; and determining, inresponse to detecting that the triggering event has occurred, whether atriggering condition associated with the emergency call is satisfied,wherein the triggering condition includes a current value of apreviously-initiated count-up timer being greater than a pre-determinedthreshold value; wherein the pre-determined threshold value correspondsto a value distinguishing between: (I) insubstantial movement of thewireless communication device, wherein the wireless device is presumedto be moving rapidly in and out of subdivisions of the wirelesscommunication network; and (II) substantial movement of the wirelesscommunication device, wherein the wireless device is presumed to not bemoving rapidly in and out of subdivisions of the wireless communicationnetwork.
 11. The system of claim 10, wherein: the operation ofdetermining whether the triggering condition is satisfied is performedin a determination operation; and the operations further comprisereturning, in response to determining that the triggering condition isnot satisfied, to the determining operation.
 12. The system of claim 10,wherein the operations further comprise initializing the count-up timer.13. The system of claim 12, wherein the operation of detecting whetherthe triggering event has occurred is performed after initializing thecount-up timer.
 14. The system of claim 10, wherein the pre-determinedthreshold value corresponds to a time period related to a desired timefrequency with which position updates should be provided to the publicsafety answering point.
 15. The system of claim 10, wherein theoperations further comprise determining, in response to determining thatthe triggering condition is satisfied, whether an automatic provision ofupdated location estimates feature has been enabled for the publicsafety answering point.
 16. A computer-readable storage devicecomprising computer-executable instructions that, when executed by aprocessor, cause the processor to perform operations, for processing anemergency call between a wireless communication device and a publicsafety answering point, comprising: detecting, by a component of awireless communication network, whether a triggering event associatedwith the emergency call has occurred, wherein the triggering eventincludes handover of the emergency call from a first subdivision of thewireless communication network to a second subdivision of the wirelesscommunication network; and determining, in response to detecting thatthe triggering event has occurred, whether a triggering conditionassociated with the emergency call is satisfied, wherein the triggeringcondition includes a current value of a previously-initiated count-uptimer being greater than a pre-determined threshold value; wherein thepre-determined threshold value corresponds to a value distinguishingbetween: (I) insubstantial movement of the wireless communicationdevice, wherein the wireless device is presumed to be moving rapidly inand out of subdivisions of the wireless communication network; and (II)substantial movement of the wireless communication device, wherein thewireless device is presumed to not be moving rapidly in and out ofsubdivisions of the wireless communication network.
 17. Thecomputer-readable storage device of claim 16, wherein: the operation ofdetermining whether the triggering condition is satisfied is performedin a determination operation; and the operations further comprisereturning, in response to determining that the triggering condition isnot satisfied, to the determining operation.
 18. The computer-readablestorage device of claim 16, wherein: the operations further compriseinitializing the count-up timer; and the operation of detecting whetherthe triggering event has occurred is performed after initializing thecount-up timer.
 19. The computer-readable storage device of claim 16,wherein the pre-determined threshold value corresponds to a time periodrelated to a desired time frequency with which position updates shouldbe provided to the public safety answering point.
 20. Thecomputer-readable storage device of claim 16, wherein the operationsfurther comprise determining, in response to determining that thetriggering condition is satisfied, whether an automatic provision ofupdated location estimates feature has been enabled for the publicsafety answering point.